Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
Records 1-6 (of 6 Records) |
Query Trace: Winters AM[original query] |
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Targeting indoor residual spraying for malaria using epidemiological data: a case study of the Zambia experience
Pinchoff J , Larsen DA , Renn S , Pollard D , Fornadel C , Maire M , Sikaala C , Sinyangwe C , Winters B , Bridges DJ , Winters AM . Malar J 2016 15 (1) 11 BACKGROUND: In Zambia and other sub-Saharan African countries affected by ongoing malaria transmission, indoor residual spraying (IRS) for malaria prevention has typically been implemented over large areas, e.g., district-wide, and targeted to peri-urban areas. However, there is a recent shift in some countries, including Zambia, towards the adoption of a more strategic and targeted IRS approach, in coordination with increased emphasis on universal coverage of long-lasting insecticidal nets (LLINs) and effective insecticide resistance management. A true targeted approach would deliver IRS to sub-district areas identified as high-risk, with the goal of maximizing the prevention of malaria cases and deaths. RESULTS: Together with the Government of the Republic of Zambia, a new methodology was developed applying geographic information systems and satellite imagery to support a targeted IRS campaign during the 2014 spray season using health management information system data. DISCUSSION/CONCLUSION: This case study focuses on the developed methodology while also highlighting the significant research gaps which must be filled to guide countries on the most effective strategy for IRS targeting in the context of universal LLIN coverage and evolving insecticide resistance. |
Malaria surveillance in low-transmission areas of Zambia using reactive case detection
Larsen DA , Chisha Z , Winters B , Mwanza M , Kamuliwo M , Mbwili C , Hawela M , Hamainza B , Chirwa J , Craig AS , Rutagwera MR , Lungu C , Ngwenya-Kangombe T , Cheelo S , Miller JM , Bridges DJ , Winters AM . Malar J 2015 14 (1) 465 BACKGROUND: Repeat national household surveys suggest highly variable malaria transmission and increasing coverage of high-impact malaria interventions throughout Zambia. Many areas of very low malaria transmission, especially across southern and central regions, are driving efforts towards sub-national elimination. CASE DESCRIPTION: Reactive case detection (RCD) is conducted in Southern Province and urban areas of Lusaka in connection with confirmed incident malaria cases presenting to a community health worker (CHW) or clinic and suspected of being the result of local transmission. CHWs travel to the household of the incident malaria case and screen individuals living in adjacent houses in urban Lusaka and within 140 m in Southern Province for malaria infection using a rapid diagnostic test, treating those testing positive with artemether-lumefantrine. DISCUSSION: Reactive case detection improves access to health care and increases the capacity for the health system to identify malaria infections. The system is useful for targeting malaria interventions, and was instrumental for guiding focal indoor residual spraying in Lusaka during the 2014/2015 spray season. Variations to maximize impact of the current RCD protocol are being considered, including the use of anti-malarials with a longer lasting, post-treatment prophylaxis. CONCLUSION: The RCD system in Zambia is one example of a malaria elimination surveillance system which has increased access to health care within rural communities while leveraging community members to build malaria surveillance capacity. |
Enhanced surveillance and data feedback loop associated with improved malaria data in Lusaka, Zambia
Chisha Z , Larsen DA , Burns M , Miller JM , Chirwa J , Mbwili C , Bridges DJ , Kamuliwo M , Hawela M , Tan KR , Craig AS , Winters AM . Malar J 2015 14 (1) 222 BACKGROUND: Accurate and timely malaria data are crucial to monitor the progress towards and attainment of elimination. Lusaka, the capital city of Zambia, has reported very low malaria prevalence in Malaria Indicator Surveys. Issues of low malaria testing rates, high numbers of unconfirmed malaria cases and over consumption of anti-malarials were common at clinics within Lusaka, however. The Government of Zambia (GRZ) and its partners sought to address these issues through an enhanced surveillance and feedback programme at clinic level. METHODS: The enhanced malaria surveillance programme began in 2011 to verify trends in reported malaria, as well as to implement a data feedback loop to improve data uptake, use, and quality. A process of monthly data collection and provision of feedback was implemented within all GRZ health clinics in Lusaka District. During clinic visits, clinic registers were accessed to record the number of reported malaria cases, malaria test positivity rate, malaria testing rate, and proportion of total suspected malaria that was confirmed with a diagnostic test. RESULTS AND DISCUSSION: Following the enhanced surveillance programme, the odds of receiving a diagnostic test for a suspected malaria case increased (OR = 1.54, 95 % CI = 0.96-2.49) followed by an upward monthly trend (OR = 1.05, 95 % CI = 1.01-1.09). The odds of a reported malaria case being diagnostically confirmed also increased monthly (1.09, 95 % CI 1.04-1.15). After an initial 140 % increase (95 % CI = 91-183 %), costs fell by 11 % each month (95 % CI = 5.7-10.9 %). Although the mean testing rate increased from 18.9 to 64.4 % over the time period, the proportion of reported malaria unconfirmed by diagnostic remained high at 76 %. CONCLUSIONS: Enhanced surveillance and implementation of a data feedback loop have substantially increased malaria testing rates and decreased the number of unconfirmed malaria cases and courses of ACT consumed in Lusaka District within just two years. Continued support of enhanced surveillance in Lusaka as well as national scale-up of the system is recommended to reinforce good case management and to ensure timely, reliable data are available to guide targeting of limited malaria prevention and control resources in Zambia. |
Modular laboratories--cost-effective and sustainable infrastructure for resource-limited settings.
Bridges DJ , Colborn J , Chan AS , Winters AM , Dengala D , Fornadel CM , Kosloff B . Am J Trop Med Hyg 2014 91 (6) 1074-8 High-quality laboratory space to support basic science, clinical research projects, or health services is often severely lacking in the developing world. Moreover, the construction of suitable facilities using traditional methods is time-consuming, expensive, and challenging to implement. Three real world examples showing how shipping containers can be converted into modern laboratories are highlighted. These include use as an insectary, a molecular laboratory, and a BSL-3 containment laboratory. These modular conversions have a number of advantages over brick and mortar construction and provide a cost-effective and timely solution to offer high-quality, user-friendly laboratory space applicable within the developing world. |
Spatial risk assessments based on vector-borne disease epidemiologic data: importance of scale for West Nile virus disease in Colorado
Winters AM , Eisen RJ , Delorey MJ , Fischer M , Nasci RS , Zielinski-Gutierrez E , Moore CG , Pape WJ , Eisen L . Am J Trop Med Hyg 2010 82 (5) 945-53 We used epidemiologic data for human West Nile virus (WNV) disease in Colorado from 2003 and 2007 to determine 1) the degree to which estimates of vector-borne disease occurrence is influenced by spatial scale of data aggregation (county versus census tract), and 2) the extent of concordance between spatial risk patterns based on case counts versus incidence. Statistical analyses showed that county, compared with census tract, accounted for approximately 50% of the overall variance in WNV disease incidence, and approximately 33% for the subset of cases classified as West Nile neuroinvasive disease. These findings indicate that sub-county scale presentation provides valuable risk information for stakeholders. There was high concordance between spatial patterns of WNV disease incidence and case counts for census tract (83%) but not for county (50%) or zip code (31%). We discuss how these findings impact on practices to develop spatial epidemiologic data for vector-borne diseases and present data to stakeholders. |
Assessing human risk of exposure to plague bacteria in northwestern Uganda based on remotely sensed predictors
Eisen RJ , Griffith KS , Borchert JN , MacMillan K , Apangu T , Owor N , Acayo S , Acidri R , Zielinski-Gutierrez E , Winters AM , Enscore RE , Schriefer ME , Beard CB , Gage KL , Mead PS . Am J Trop Med Hyg 2010 82 (5) 904-11 Plague, a life-threatening flea-borne zoonosis caused by Yersinia pestis, has most commonly been reported from eastern Africa and Madagascar in recent decades. In these regions and elsewhere, prevention and control efforts are typically targeted at fine spatial scales, yet risk maps for the disease are often presented at coarse spatial resolutions that are of limited value in allocating scarce prevention and control resources. In our study, we sought to identify sub-village level remotely sensed correlates of elevated risk of human exposure to plague bacteria and to project the model across the plague-endemic West Nile region of Uganda and into neighboring regions of the Democratic Republic of Congo. Our model yielded an overall accuracy of 81%, with sensitivities and specificities of 89% and 71%, respectively. Risk was higher above 1,300 meters than below, and the remotely sensed covariates that were included in the model implied that localities that are wetter, with less vegetative growth and more bare soil during the dry month of January (when agricultural plots are typically fallow) pose an increased risk of plague case occurrence. Our results suggest that environmental and landscape features play a large part in classifying an area as ecologically conducive to plague activity. However, it is clear that future studies aimed at identifying behavioral and fine-scale ecological risk factors in the West Nile region are required to fully assess the risk of human exposure to Y. pestis. |
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